In recent years, from the viewpoints of environmental protection, resource saving, CO2 reduction, etc., large-scale solar photovoltaic power generation facilities have spread which are called a “mega solar” or a “giga solar” and in which many solar battery arrays are arranged side by side on the ground including flat land and inclined land or on a deck such as the roof of a building. However, generally, a solar battery array, which is formed by arranging a plurality of solar photovoltaic power generation panels (solar battery modules) in a flat manner so as to have its short side of several meters and its long side of from several meters to several tens of meters, is great in size and in weight, and is liable to receive wind pressure by being disposed at a predetermined inclination angle in consideration of light-receiving efficiency, and is susceptible to earthquake shocks, and therefore this solar battery array is required to have great structural strength, and is required to cope with ground surface irregularity when it is installed on the ground or to cope with uneven ground settlement after it is installed on the ground, and is required to achieve installing-operation facilitation, cost reductions, etc.
According to a conventional method, a mount that is made of, for example, shaped steel having a specific shape in cross section and on which solar photovoltaic power generation panels are placed is constructed while using concrete stakes or foundations as bases, and this conventional method has been heavily employed as a means for installing the solar battery array on the ground or on a deck. Typical structures of this mount include a structure (For example, Japanese Published Unexamined Patent Application No. 2011-220096 (FIG. 1, FIG. 42, FIG. 43)) in which a plurality of support pillars are spaced and erected along a longitudinal direction (right-left direction) of the solar battery array, and an upper end of each support pillar is connected to an intermediate position of a vertical bar along a forwardly/rearwardly inclined direction of a mount frame that supports solar photovoltaic power generation panels, and an inclined arm is connected to a position between a barrel part of each support pillar and a front side of or both front and rear sides of each vertical bar and a structure (For example, Japanese Registered Utility Model No. 3171824 (FIG. 1)) in which a mount frame that supports solar photovoltaic power generation panels is supported by support pillars arranged on the front/rear and right/left sides, and diagonal and horizontal reinforcing bars are connected together between the front/rear adjoining support pillars and between the right/left adjoining support pillars.